Efficient Visible-Light Driven Photothermal Conversion of CO2 to Methane by Nickel Nanoparticles Supported on Barium Titanate

Solar-driven methanation represents a potentially cost-efficient and environmentally friendly route for the direct hydrogenation of CO₂. Recently, photothermal catalysis, which involves the combination of both photochemical and thermochemical pathways, has emerged as a promising strategy for the production of solar fuels. For a photothermal catalyst to efficiently convert CO₂ under illumination, in the absence of external heating, effective light harvesting, an excellent photothermal conversion and efficient active sites are required. Here, a new composite catalyst consisting of Ni nanoparticles supported on barium titanate that, under optimal reaction conditions, is able to hydrogenate CO₂ to CH₄ at nearly 100% selectivity with production rates as high as 103.7 mmol g^–1 h^–1 under both UV–visible and visible irradiation (production rate: 40.3 mmol g⁻¹ h^–1) is reported. Mechanistic studies suggest that reaction mostly proceeds through a nonthermal hot-electron-driven pathway, with a smaller thermal contribution.